If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

The Staff and Management of getDPI apologise for the inconvenience caused by the "Front page" being out of service. Work crews have been dispatched to identify the source of the difficulty.

Pentax 645Z vs Canon 5DSR

Got the 5DSR last week, in my Quixotic search for the best IQ and performance in the smallest package.

Tested it in the backyard against the Pentax. I've posted this elsewhere on another forum, but this is a better place to discuss this.

Obviously this is just a field test, with backyard foliage, brick wall of the garage etc. I tested initially with handheld shots, increasing the ISO to keep the shutter speed constant. I then used a tripod to keep the ISO constant at 100, using MLUP and self timer. Tested from wide open to f16 on both cameras.

I was looking for sharpness, resolution, noise and an overall feel for the images. Issues like CA, distortion, center vs edge sharpness etc are obviously lens dependent and would be harder to compare. Still, it was interesting to see if the Pentax lenses hold up against the best Canon has to offer.

Sharpness/resolution: Pentax is clearly better, expected them to be near equal.

Noise: Again, Pentax much cleaner, even in a well exposed image, ISO1600 is about the same as ISO 800 on the Canon. If you have to pull up shadows it gets worse on the Canon rapidly. Again, I expected this.

Overall feel, image look: I know this is subjective but I like the output from the Pentax more. There is a crispness and although the Canon by default saturates the images more, there is a slightly subdued but more appealing quality to the Pentax files, small details are clearer and yet 'smoother'. There is a certain 'muddiness' in the Canon images.

Lens comparison:

I was very impressed with the performance of the Pentax lenses, particularly the DFA 55 f2.8. It is significantly sharper than the Canon 24-70 especially at the edges at all apertures. Since I was about 40 feet from the subject, I did not see the problems with field curvature etc that others have reported.

Even the much older FA 45-85 (I bought mine used for around $700) is better than the 16-35 f4 IS which is one of Canon's sharpest wide zooms. The Canon is better at the edges wide open, but the Pentax catches up at f8 and remains sharper at the center throughout.

The Pentax is of course a larger package overall, heavier, more expensive (the lenses I have are cheaper than Canon though), has a slower frame rate and the AF is no good for action.

However, if I was looking for the best IQ for landscape work, the Pentax is a better choice despite the limitations.

I wonder how much better it would be given better lenses, esp ultra-wide. The new 28-45 though huge and expensive is said to be very sharp.

Re: Pentax 645Z vs Canon 5DSR

I think no one would have been too surprised by this, the pixel count is the only thing that's roughly equal between these cameras. Maybe in an "ideal" studio environment the differences would've been harder to spot, but you're not paying 2x the Canon's cost for nothing either.

As far as the 28-45 goes, all of I've heard about the lens is how absurdly good it is, which seriously making me consider buying it. There are very few WA choices for the Pentax anyway, so it's not like you can flip a coin here, it's having a coin to flip.

Re: Pentax 645Z vs Canon 5DSR

Neither of you guys should be disappointed with the 28-45. I know mine is my favorite landscape lens, bar none.

As for the comparisons, it's simple. The photo sites are larger on the Pentax than on the Canon.

I bought the Canon simply because I was looking for a smaller package with the quality of the Pentax and where I could put the lenses I already own to good use. What surprised me is that the Pentax lenses are able to hold their own against the latest and best from Canon.

Re: Pentax 645Z vs Canon 5DSR

I need to play with more raw files but so far the 5DSR files have not impressed me that much. They are good but I only see slight improvement over the 5D3 files in other image quality aspects (using LR6) besides detail (which can be awesome on the 5DS/R).

I mean no way do the 5DSR files (using Canon's latest L glass) have the bite of what I have seen from the IQ150/250 and the 645Z and MUCH less than what I see with my IQ160 and Rodenstock glass. Again, in wide angle landscapes. There is a huge difference. Also, when pushed, sky color gradations tend to break up sooner on the 5DS/R files I have played with. Shadows have still some of that Canon murkiness, better but still not nearly as clean as the Nikon and Sony sensors.

I played with some 5DSR files of a Landscape in lower light but daylight conditions. The scene had wild grass, a pond with a fallen tre in the foreground, pine trees and brush in the middle plus a rocky mountain in the background with a pretty pronounced ridgeline. Again, perfect for testing and comparing cameras.

Looking forward to getting my hands on some A7RII files of a similar landscape to compare.

One good thing about the Canon files is that they are pretty much free from dust spots. That is a big time saver for those that shoot and process a lot of images. The same applies to the 5D3. Nikon and Sony sensors get FILTHY really quick and stay that way.

Overall the 645Z produces a much nicer file even though glass might not be as nice except for the new lenses, which are VERY expensive (and the older ones if used at optimum apertures) and not as wide ranging.

Overall the 5DS/R is mostly for those who love working with the 5D3 but want more resolution (significant) and a bit nicer file to push.

Re: Pentax 645Z vs Canon 5DSR

Pradeep, I would love to examine the raw files if you are willing to share them. Happy to host them on Dropbox or Google Drive if you'd like. I am planning a similar shoot out against the A7r II when it comes out.

Re: Pentax 645Z vs Canon 5DSR

Thanks Pradeep. The consensus opinion on the 645Z vs 5DSR seems pretty clear and I have blogged about the clear lead the 645Z has over my A7R in every regard really, so your results are as expected. Carting the 645Z around with the 28-45 is like carrying almost two 5DSR plus 16-35 IS combos, however.

And yes, some of those 30 year old Pentax A series lenses run rings around new optics in terms of resolution and evenness of performance. Even the 80-160 zoom shocked me with what I got for £130! So few FF lenses were designed with anything like 50MP in mind, whereas those Pentax lenses were designed to cover a larger piece of film, so we get that central sweet spot on the 44x33mm sensor.

Ken, I have never used Rodenstock glass on digital but I know what I saw on film. Schneider optics seemed gentler and similarly high in resolution, but the Rodenstocks always had a real bits with oodles of global and microcontrast. my 5x4 negs were clearly different to those from my Schneiders the second they were plucked from the wash.

I'd never thought about the dust and marks issue, but now you mention it... its so true! My 5D III sensor is clean as a whistle.

Re: Pentax 645Z vs Canon 5DSR

I would tend to agree, keeping the A7r clean is a bit of a hassle. When I used it with the Acra DSLR2, the sensor did get pretty dirty and quickly, however pretty much any mirrorless I have worked with has the same issues. I never had to wet clean the Sony, but did have to work with the rocket blower quite a bit.

My D800e and D810 have been very clean cameras, in line with my old Canon 5D MK2. I would agree that Canon did figure something out as in 3 years of heavy use I never once had to wet clean my 5D MK2 and 1.5 years with a 6D. Glad to see that Canon passed that tech forward. Where as I really can't remember how many times I had to clean both my 1ds MKI and MKII especially the corners.

Nikon's internal cleaning seems to get the job done for me. I have had my 800e now almost 3 years and never had to wet clean or blow it off. The D810 is the same. I do change out lenses a lot so I would say Nikon does a good job on sensor cleans.

You want to talk dirty, (just kidding), then use a Phase One back on a tech camera for 1 day. That's going to show dirt, and a lot of it. Especially outdoors. To their credit, Phase does offer a great cleaning kit and I have learned to use the Leaf wipes, they are an amazing material. Spring/Fall, my heaviest use for Phase, pretty much several rocket blower cleanings on a single day and then probably at least 1 wet clean (only solution B) a month. I have also found that the LCC dust correction more often then not will not work on many spots and instead makes them worse with a white ring around them, IQ160/180/260. Only seems to happen on a few spots, but does create more post processing issues.

Re: Pentax 645Z vs Canon 5DSR

Originally Posted by AreBee

Paul,

Is dust suppression a selectable option of an LCC or is it mandatory?

It's a selectable option. You can tell C1 to turn off both color cast corrections and the dust spots fix for the LCC. I tend to turn off the dust fix as more often than not as I get several corrections that end up as inverse corrections, a larger white spot.

Re: Pentax 645Z vs Canon 5DSR

It is a pain when the dust moves or the LCC doesn't line up perfectly. But an LCC taken immediately before or after a capture will usually do a good job on dust. I've shot LCCs on Leica and Sony cameras just for dust removal.

Re: Pentax 645Z vs Canon 5DSR

Originally Posted by thedigitalbean

Pradeep, I would love to examine the raw files if you are willing to share them. Happy to host them on Dropbox or Google Drive if you'd like. I am planning a similar shoot out against the A7r II when it comes out.

Aravind, no problems, I will upload them to your dropbox folder later tonight or tomorrow. Just let me have the link via PM.

FWIW, I also have the A7RII on order. Still continuing to search for perfection in a small package........

Re: Pentax 645Z vs Canon 5DSR

Originally Posted by turtle

Thanks Pradeep. The consensus opinion on the 645Z vs 5DSR seems pretty clear and I have blogged about the clear lead the 645Z has over my A7R in every regard really, so your results are as expected. Carting the 645Z around with the 28-45 is like carrying almost two 5DSR plus 16-35 IS combos, however.

And yes, some of those 30 year old Pentax A series lenses run rings around new optics in terms of resolution and evenness of performance. Even the 80-160 zoom shocked me with what I got for £130! So few FF lenses were designed with anything like 50MP in mind, whereas those Pentax lenses were designed to cover a larger piece of film, so we get that central sweet spot on the 44x33mm sensor.

Ken, I have never used Rodenstock glass on digital but I know what I saw on film. Schneider optics seemed gentler and similarly high in resolution, but the Rodenstocks always had a real bits with oodles of global and microcontrast. my 5x4 negs were clearly different to those from my Schneiders the second they were plucked from the wash.

I'd never thought about the dust and marks issue, but now you mention it... its so true! My 5D III sensor is clean as a whistle.

Yes, the consensus is building up and it's good for the Pentax. Amazing how good those old lenses are. For landscape photography I don't mind the weight as long as there is no long hikes involved.

My own experience with dust has been different. My worst offender is the Canon 1DX. Somehow it always manages to get dirty.

On my recent trip to Africa I took three bodies (well, four actually). My main cameras were the 645Z, the 1DX and the 7D2, with the A7R thrown in for wide angle shots and casual 'about the camp' stuff.

The 1DX had the 70-200 f4 on it and the 7D2 the 100-400L MkII. The 1DX sensor was cleaned professionally by a local store before I took it. The other cameras were clean on sensor check before the trip.

I did not change the lenses on the Canon cameras during the entire trip, not even when traveling all day by van between locations. They stayed on until the final day before flying back.

The Pentax was a different story, I changed lenses at least 20 times during the day depending upon the scene, right in the field with dust blowing around. The only spot it got on was on the second last day, a large blob that was obvious even on a thumbnail, it took me half a minute to get rid of it with the gelstick.

Same with the Sony, I changed lenses several times though not as much as on the Pentax, again, no spots.

Returning home, the 1DX did have spots on the sensor. Perhaps the professional guy did not clean it perfectly, I don't know. But the Pentax and Sony were absolutely spotless (other than the one incident above).

I used a very quick two hand technique when changing lenses on the 645Z, allowing the camera to be exposed for less than 1 second.

Re: Pentax 645Z vs Canon 5DSR

Originally Posted by algrove

The best package you have in your head-artistic expression.

Agree completely

But we are restless spirits, else we would have never evolved. I dare say my first DSLR, the Canon D60 was one of the most thrilling cameras I've ever used. Coming from a film Pentax (strange, but I'm back with Pentax after 20 years), it was a joy to behold and I couldn't get over the fact that I did not have to worry about running out of film any more.

Since then the search has continued. Unfortunately I suffer severely from GAS and must buy/try every major update of every gadget I own. It is a malady for which there is no cure. My wife contributes to this by not protesting too much at my latest acquisition. I guess she puts up with me because my symptoms are limited to technology and do not extend to other women

Re: Pentax 645Z vs Canon 5DSR

The large and heavy 645 SLR lenses only make sense for sensors larger than the now typical ~33x44mm.

ASAIK Only Leica makes a whole set of lenses for that sensor size (and since the system is a whole new design it has a much shorter focal flange distance which makes adapting 645 lenses to it a breeze)

IIRC the Hasselblad H 24 and 28mm lenses are for the smaller sensors.

Pentax has the 645 DA lenses (the 28-45mm being the flagship IMHO) which are designed for the smaller than 645 digital sensors but are still quit large because they have to deal with the inherited (from the 645 format) large focal flange distance from the film days.

The Phase / Mamiya / Schneider system is all about 645 lenses still. They some are massive but can handle the large 60-80mp digital sensors no problem (and of course film). This system is open to the possibility of large CMOS sensors if they ever come out. The others are committed to the smaller 33x44mm format (30x45mm in the case of the Leica S systems)

Re: Pentax 645Z vs Canon 5DSR

I do not agree that the older Pentax film era lenses don't make sense on 33x44. Most of the film era Pentax 645 lenses are actually lighter than the later DA models designed for the smaller digital sensor. Compare the 120mm Macro (700g) with the 90mm Macro (1000g, albeit with SR). The modern 28-45, as amazing as it is (and if anyone wants to see some full-width samples I posted some here), weighs 1500g, which is over 600g more than the older 45-85 FA, for example (I know this is apples to oranges, but you get the idea).

I think the greater weight of the modern DA lenses is the fact that the digital sensors are exceedingly demanding and the new lenses have a lot of glass in them! Make no mistake, however, many of the older lenses are very good indeed. My 35mm A is astonishingly good and weighs less than 500g. The 75mm FA is sharp as a tack and weighs just over 200g and takes a 58mm filter! Quite frankly, you'd have to be window licking mad to pay five times more for a super duper DA version of the same lenses when some of the legacy lenses are still so good on the 645Z. Maybe a future 70MP sensor will be more demanding, but right now the existence of so many good quality affordable legacy lenses is one of the main selling points of the 645Z IMHO. They're not all great and there are some real dogs, but a bit of research is rewarded with huge savings.

As a point of interest, if you scale up the 42mp sensor in the A7R II to 33x44, you get 71 MP. At this point, as long as the lenses can keep up (and I have no doubt the best lenses will), further increases in MP will make absolutely no difference to how good you 50" prints look to the majority of eyes and so I feel the 33x44mm sensor will prove just big enough. Sure, bigger formats will go higher, but whether mortals have any need for it is debatable.

Re: Pentax 645Z vs Canon 5DSR

Originally Posted by Ken_R

Pentax has the 645 DA lenses (the 28-45mm being the flagship IMHO) which are designed for the smaller than 645 digital sensors but are still quit large because they have to deal with the inherited (from the 645 format) large focal flange distance from the film days.

As far as I know all the new lenses cover full 645, the 55 & 90mm 2.8 have been 100% confirmed to do so, one of the 25mm variants has a reduced hood that avoids vignetting on film, and I'm not sure about the 28-45, but somehow I doubt that a lens that enormous doesn't have the capability. Even the absurdly wide Canon 11-24mm has been shown to cover 33x44 at 15mm, and possibly more if the hood is shaved off.

Re: Pentax 645Z vs Canon 5DSR

The 28-45 is classified as DA and not DFA which suggests that it doesn't cover full frame 645. I am not certain, but I think that's right... Certainly that's the way the notation is using with the 25mm lenses; the DFA covers full frame, the DA version does not.